We have been researching/refining the default ranges for GBUdb. Here are our latest reference settings. These are conservative for large systems (500/min) and should be even more conservative for smaller systems.

Smaller systems that experience lower message rates will tend to have lower confidence numbers in their GBUdb due to fewer message interactions. If you run a system that sees fewer than 500 messages per minute then you may achieve higher capture rates before FPs with lower confidence values in some of your ranges.

Another way smaller systems may adjust their GBUdb sensitivity is to adjust the time between condensation from one day to two days (or more) or to eliminate the time based trigger and rely on the memory usage trigger instead (by triggering condensation events only when a specific memory threshold has been reached). The latter method is typically recommended for systems with fewer than 10 messages per minute.

All of the above tuning recommendations are somewhat experimental since GBUdb is relatively new and at present sparsely populated (about 300 participating nodes at present). As time goes on we will all learn more about how to optimize GBUdb - please experiment cautiously and scientifically (one change at a time and understand what has happened) and please share your results.

Here is the current reference:

<regions>
  <white on-off='on' symbol='0'>
    <edge probability='-1.0' confidence='0.4'/>
    <edge probability='-0.8' confidence='1.0'/>
    <panic on-off='on' rule-range='1000'/>
  </white>
  <caution on-off='on' symbol='40'>
    <edge probability='0.4' confidence='0.0'/>
    <edge probability='0.8' confidence='0.5'/>
  </caution>
  <black on-off='on' symbol='63'>
    <edge probability='0.8' confidence='0.2'/>
    <edge probability='0.8' confidence='1.0'/>
    <truncate on-off='on' probability='0.9' peek-one-in='5' symbol='20'/>
    <sample on-off='on' probability='0.8' grab-one-in='5' passthrough='no' passthrough-symbol='0'/>
  </black>
</regions> 			

If you are running the new SNF and you haven't checked your GBUdb range settings in a while this might be a good time to make some adjustments ;-) Some of the settings in previous releases were less conservative and some were less aggressive -- all were backed by less experience (of course).